Refs #101049  Fix comment typo.
Refs #101049  Add a per-cob refcount to know how many face queues it is in.

This permits us to try to avoid discarding content that is about to be sent.

There would be a DOS risk if a face accumulates a lot of queued entries,
so if there are too many referenced items at the head of the expiry line,
go ahead and take the first one anyway.
Refs #101049  Enforce the capacity as the limit, not one fewer.
Refs #101049  Try harder to avoid tossing queued content
Refs #101049  Avoid bumping the ref count again if the content is already queued.
Refs #101049  Allow the cache limit to be a bit over capacity, to allow for some queue entries.
Refs #101049  Remove some obsolete measures for simulating the effect of a null cache.

With the ref counting in place, this is no longer necessary; we can just set capacity to 0.
Refs #101032  Increase timeouts in test_checked_startwrite - sometimes schedulers do not give us cycles for a surprisingly long time
Refs #101049  Merge remote-tracking branch 'origin/101049-cache-replacement'

* origin/101049-cache-replacement:
  Refs #101049  Remove some obsolete measures for simulating the effect of a null cache.
  Refs #101049  Allow the cache limit to be a bit over capacity, to allow for some queue entries.
  Refs #101049  Avoid bumping the ref count again if the content is already queued.
  Refs #101049  Try harder to avoid tossing queued content
  Refs #101049  Enforce the capacity as the limit, not one fewer.
  Refs #101049  Add a per-cob refcount to know how many face queues it is in.
  Refs #101049  Fix comment typo.
Refs #101045, 101049, 100118  Add 101049 to NEWS
Refs #101045, 101049  Bump CCN_API_VERSION to 8002 for ccnx-0.8.1
Refs #101045  Rebuild man pages for ccnx-0.8.1